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S-nitrosylation/Denitrosylation and Apoptosis of Immune Cells 被引量:6
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作者 Shaojin Duan Chang Chen 《Cellular & Molecular Immunology》 SCIE CAS CSCD 2007年第5期353-358,共6页
Nitric oxide (NO) as an immunoregulatory molecule, predominantly depending on S-nitrosylation, acts as a versatile player that executes its regulation and signal transduction for exerting its multi-functions and ple... Nitric oxide (NO) as an immunoregulatory molecule, predominantly depending on S-nitrosylation, acts as a versatile player that executes its regulation and signal transduction for exerting its multi-functions and pleiotropy. Apoptosis of immune cells is an intricate process coupled with positive/negative selection depending on integrated diverse endogenous and exogenous signals and functions to sustain homeostasis in the immune system. Here, the dual roles of NO depending on its concentration in apoptosis are reviewed, breeding up a switch mode in the apoptotic process. Following comments of different switches from apoptosis-death, a new finding of checkpoint (early fluorescence point) of GSNO-initiated thymocyte apoptosis and NOS-GSNOR double control are highlighted. Moreover, S-nitrosylation/denitrosylation, being as a redox switch, logically approaches to networks of metabolism itself and further accesses the neuroendicrine-immune-free radical network as a whole. Moreover, the host defense mediated by NO on pathogens, via protein S-nitrosylation are also discussed. 展开更多
关键词 immune cell nitric oxide APOPTOSIS S-nitrosylation/denitrosylation switch host defense
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The dichotomous role of TGF-β in controlling liver cancer cell survival and proliferation 被引量:7
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作者 Kegui Zhang Meiping Zhang +2 位作者 Zhijun Luo Zhili Wen Xiaohua Yan 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2020年第9期497-512,共16页
Hepatocellular carcinoma(HCC) is the major form of primary liver cancer and one of the most prevalent and life-threatening malignancies globally. One of the hallmarks in HCC is the sustained cell survival and prolifer... Hepatocellular carcinoma(HCC) is the major form of primary liver cancer and one of the most prevalent and life-threatening malignancies globally. One of the hallmarks in HCC is the sustained cell survival and proliferative signals, which are determined by the balance between oncogenes and tumor suppressors.Transforming growth factor beta(TGF-β) is an effective growth inhibitor of epithelial cells including hepatocytes, through induction of cell cycle arrest, apoptosis, cellular senescence, or autophagy. The antitumorigenic effects of TGF-β are bypassed during liver tumorigenesis via multiple mechanisms.Furthermore, along with malignant progression, TGF-β switches to promote cancer cell survival and proliferation. This dichotomous nature of TGF-β is one of the barriers to therapeutic targeting in liver cancer. Thereafter, understanding the underlying molecular mechanisms is a prerequisite for discovering novel antitumor drugs that may specifically disable the growth-promoting branch of TGF-β signaling or restore its tumor-suppressive arm. This review summarizes how TGF-β inhibits or promotes liver cancer cell survival and proliferation, highlighting the functional switch mechanisms during the process. 展开更多
关键词 TGF-Β Hepatocellular carcinoma(HCC) cell survival PROLIFERATION Functional switch Signaling regulation
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VLAN技术综述 被引量:5
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作者 陈宇晓 冯江华 何均 《兵工自动化》 2002年第6期41-44,共4页
传统局域网中的站点被束缚在所处网络物理位置上,不能按需划分逻辑子网、共享传输信道冲突和广播风暴等,故提出虚拟局域网(Virtual LAN)概念。VLAN的基础是LAN的帧交换和信元交换,每个LAN段通过VLAN网络管理软件与其它LAN段建立连接并... 传统局域网中的站点被束缚在所处网络物理位置上,不能按需划分逻辑子网、共享传输信道冲突和广播风暴等,故提出虚拟局域网(Virtual LAN)概念。VLAN的基础是LAN的帧交换和信元交换,每个LAN段通过VLAN网络管理软件与其它LAN段建立连接并可动态地组成新VLAN。VLAN的节点设备可连接到不同交换机的多台集线器上,物理位置的变动不影响其所属的VLAN。VLAN技术包括VLAN的划分、VLAN的信息传递、VLAN的配置、VLAN间的通信及其标准。该技术能充分满足用户对网络灵活性和扩展性的要求,对隔离网络故障、高效率分配网络骨干带宽和降低网络成本提供了技术保障。 展开更多
关键词 VLAN技术 虚拟局域网 交换技术 帧交换 信元交换
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Enabling Energy Efficiency in 5G Network 被引量:4
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作者 LIU Zhuang GAO Yin +2 位作者 LI Dapeng CHEN Jiajun HAN Jiren 《ZTE Communications》 2021年第1期20-29,共10页
The mobile Internet and Internet of Things are considered the main driving forc⁃es of 5G,as they require an ultra-dense deployment of small base stations to meet the in⁃creasing traffic demands.5G new radio(NR)access ... The mobile Internet and Internet of Things are considered the main driving forc⁃es of 5G,as they require an ultra-dense deployment of small base stations to meet the in⁃creasing traffic demands.5G new radio(NR)access is designed to enable denser network deployments,while leading to a significant concern about the network energy consump⁃tion.Energy consumption is a main part of network operational expense(OPEX),and base stations work as the main energy consumption equipment in the radio access network(RAN).In order to achieve RAN energy efficiency(EE),switching off cells is a strategy to reduce the energy consumption of networks during off-peak conditions.This paper intro⁃duces NR cell switching on/off schemes in 3GPP to achieve energy efficiency in 5G RAN,including intra-system energy saving(ES)scheme and inter-system ES scheme.Addition⁃ally,NR architectural features including central unit/distributed unit(CU/DU)split and dual connectivity(DC)are also considered in NR energy saving.How to apply artificial in⁃telligence(AI)into 5G networks is a new topic in 3GPP,and we also propose a machine learning(ML)based scheme to save energy by switching off the cell selected relying on the load prediction.According to the experiment results in the real wireless environment,the ML based ES scheme can reduce more power consumption than the conventional ES scheme without load prediction. 展开更多
关键词 cell switch off energy efficiency energy saving 5G machine learning
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血管平滑肌细胞表型转换与细胞焦亡在腹主动脉瘤中的作用及研究进展
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作者 刘欣 唐红悦 +2 位作者 郭畅 马冬 张明明 《中国比较医学杂志》 CAS 北大核心 2024年第11期100-106,共7页
腹主动脉瘤(abdominal aortic aneurysm,AAA)作为一种隐匿型致死性疾病,其背后的发展机制尚不清楚。研究已经发现血管平滑肌细胞(vascular smooth muscle cell,VSMCs)表型转换和细胞焦亡(cell pyroptosis)是与AAA产生发展密切相关的两... 腹主动脉瘤(abdominal aortic aneurysm,AAA)作为一种隐匿型致死性疾病,其背后的发展机制尚不清楚。研究已经发现血管平滑肌细胞(vascular smooth muscle cell,VSMCs)表型转换和细胞焦亡(cell pyroptosis)是与AAA产生发展密切相关的两种生物学过程,可能会成为揭示AAA发生机制的重要学说,为AAA的诊断和治疗提供新的方向。本文将通过介绍VSMCs表型转换和细胞焦亡与AAA之间的调控关系展开论述。 展开更多
关键词 细胞焦亡 表型转换 动脉粥样硬化性疾病 腹主动脉瘤
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Ikaros in B cell development and function 被引量:3
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作者 MacLean Sellars Philippe Kastner Susan Chan 《World Journal of Biological Chemistry》 CAS 2011年第6期132-139,共8页
The zinc finger transcription factor, Ikaros, is a central regulator of hematopoiesis. It is required for the development of the earliest B cell progenitors and at later stages for VDJ recombination and B cell recepto... The zinc finger transcription factor, Ikaros, is a central regulator of hematopoiesis. It is required for the development of the earliest B cell progenitors and at later stages for VDJ recombination and B cell receptors expression. Mature B cells rely on Ikaros to set the activation threshold for various stimuli, and to choose the correct antibody isotype during class switch recombination. Thus, Ikaros contributes to nearly every level of B cell differentiation and function. 展开更多
关键词 IKAROS HEMATOPOIESIS Mature B cells
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Bioinspired therapeutic platform based on extracellular vesicles for prevention of arterial wall remodeling in hypertension 被引量:2
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作者 Chen Wang Changyang Xing +6 位作者 Zhelong Li Yunnan Liu Qiaoying Li Yixiao Wang Jiao Hu Lijun Yuan Guodong Yang 《Bioactive Materials》 SCIE 2022年第2期494-504,共11页
Arterial stiffness due to the vessel remodeling is closely linked to raised blood pressure,and its physiopathologic mechanism is still not fully understood.We here aimed to explore whether extracellular vesicle(EV)med... Arterial stiffness due to the vessel remodeling is closely linked to raised blood pressure,and its physiopathologic mechanism is still not fully understood.We here aimed to explore whether extracellular vesicle(EV)mediated intercellular communication between endothelium and smooth muscle cell contribute to the blood vessel remodeling under hypertension.We here revealed that the arterial endothelial cells robustly secreted EV,which in turn could be circulated and/or directly taken up by the subendothelial smooth muscle cells(SMC).Under hypertension,the EV secretion increased and the miRNA profile changed significantly mainly due to the raised mechanical force and subsequent enhanced reactive oxygen species generation.Among the miRNA cargos in the EV,miR-320d/423-5p were found increased most significantly.In vivo delivery of miR-320d/423-5p mimics via engineered EV increased their expression in arterial vessels,recapitulating the phenotype in hypertension.In contrast,therapeutic delivery of miR-320d/423-5p inhibitors via engineered EV alleviated the phenotype in spontaneous hypertension rat model.Together,we have found that the injured endothelium due to the raised mechanical force in hypertension contributes to the arterial wall remodeling via the secreted EV.Our study has not only provided novel insights on the mechanism of hypertension associated blood vessel wall remodeling,but also shed light on therapeutic intervention of hypertension associated vascular diseases. 展开更多
关键词 HYPERTENSION Extracellular vesicles Endothelial cell Smooth muscle cell Phenotype switch microRNA
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Research on Interference Cancellation for Switched-on Small Cells in Ultra Dense Network 被引量:1
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作者 SUN Yang CHANG Yongyu +3 位作者 WANG Chao ZHANG Lu ZHANG Yu WANG Xinhui 《ZTE Communications》 2016年第B12期48-53,共6页
In ultra-dense heterogeneous networks, the co-channel inter- ference between small cells turns to be the major challenge to cell throughput improvement, especially for cell edge users. In this paper, we propose a dist... In ultra-dense heterogeneous networks, the co-channel inter- ference between small cells turns to be the major challenge to cell throughput improvement, especially for cell edge users. In this paper, we propose a distributed frequency resource al- location approach for interference cancellation, which allo- cates appropriate frequency resources when a small cell is switched on to reduce the co-channel interference to its neigh- boring small cells. This frequency resource pre-allocation aims at avoiding co-channel interference between small ceils and improving users ' throughput. The simulation results show that our proposed scheme can effectively reduce the co-chan- nel interference and achieve considerable gains in users' through put. 展开更多
关键词 ultra-dense network interference cancellation frequency resource allocation cell switch
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5G IAB基站启动建立连接过程研究 被引量:2
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作者 王俊 李小龙 +1 位作者 谢文武 廖俭武 《通信技术》 2019年第4期890-893,共4页
在5G NR研究中提出了IAB基站,IAB基站集成了无线接入链路和无线回传链路。IAB基站在启动后将作为UE来选择合适的IAB基站接入来建立网络连接,因此需要选择合适的IAB基站接入网络。提出的核心网OAM服务器动态更新IAB网络拓扑信息,以及IAB... 在5G NR研究中提出了IAB基站,IAB基站集成了无线接入链路和无线回传链路。IAB基站在启动后将作为UE来选择合适的IAB基站接入来建立网络连接,因此需要选择合适的IAB基站接入网络。提出的核心网OAM服务器动态更新IAB网络拓扑信息,以及IAB网络向待接入的IAB基站提供辅助信息方案解决了IAB基站启动后如何获取网络拓扑信息从而选择合适小区接入建立网络连接的问题。 展开更多
关键词 IAB基站 小区选择 建立连接
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细胞命运转变——谱系重编程技术研究进展 被引量:2
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作者 孙红艳 王锋 曹文广 《遗传》 CAS CSCD 北大核心 2012年第8期985-992,共8页
体细胞核移植和诱导多能干细胞技术表明已分化的体细胞可以转变命运。最近的研究再一次验证了成熟体细胞可以通过外源转录因子的导入,直接重编程为其他类型的体细胞或祖细胞。这种重编程技术称为谱系重编程(Lineage reprogramming)。这... 体细胞核移植和诱导多能干细胞技术表明已分化的体细胞可以转变命运。最近的研究再一次验证了成熟体细胞可以通过外源转录因子的导入,直接重编程为其他类型的体细胞或祖细胞。这种重编程技术称为谱系重编程(Lineage reprogramming)。这项技术不仅在再生医学领域具有广阔的应用前景,而且在动物生物技术中也应用广泛。它不但避免了伦理争议,还提供了便利的重编程方法,同时也为基因表达调控的研究提供了重要的手段。文章从谱系重编程的方式、谱系重编程的特点及应用前景等3个方面进行了综述,旨在对相关领域的研究人员起到借鉴作用。 展开更多
关键词 体细胞 谱系重编程 转录因子 命运转变
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燃料电池在特殊工程车辆领域的应用进展 被引量:2
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作者 许壮 何广利 《装备制造技术》 2018年第12期80-85,共6页
燃料电池是一种清洁高效的能源利用技术,在特殊工程车辆领域推广应用,有利于实现大气污染物SO2、NOx、PM零排放,促进温室气体CO2减排。综述了燃料电池为动力的矿山车、卡轨车、掉头机车和货运卡车的应用进展,分析了燃料电池工程车辆替... 燃料电池是一种清洁高效的能源利用技术,在特殊工程车辆领域推广应用,有利于实现大气污染物SO2、NOx、PM零排放,促进温室气体CO2减排。综述了燃料电池为动力的矿山车、卡轨车、掉头机车和货运卡车的应用进展,分析了燃料电池工程车辆替代内燃机车的技术可行性以及由此带来的环保效益,认为燃料电池工程车辆已经具备了规模化应用的条件。 展开更多
关键词 燃料电池 矿山车 卡轨车 掉头机车 卡车
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无线ATM技术前沿 被引量:1
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作者 张雯 吕四化 《中国传媒大学学报(自然科学版)》 2003年第3期55-61,共7页
介绍了无线ATM网络的技术的频率接口。分析了无线ATM(Wireless ATM)的网络体系结构、信元格式、协议分层,并着重讨论目前研究得较多的关键技术:物理层(PHY)技术、多址访问控制(MAC)协议、差错控制、位置管理和越区切换控制等。并总结了A... 介绍了无线ATM网络的技术的频率接口。分析了无线ATM(Wireless ATM)的网络体系结构、信元格式、协议分层,并着重讨论目前研究得较多的关键技术:物理层(PHY)技术、多址访问控制(MAC)协议、差错控制、位置管理和越区切换控制等。并总结了ATM Forum、ETSI对无线ATM标准化的进展情况和国际上正在开展的无线ATM研究项目以及现有的无线宽带网络的实验系统。 展开更多
关键词 无线ATM 无线宽带网络 无线接入 MAC协议 越区切换
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等离子体电极普克尔盒性能提升研究
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作者 吴振海 龙蛟 +4 位作者 李珂 田晓琳 熊迁 张君 胡东霞 《强激光与粒子束》 CAS CSCD 北大核心 2023年第6期45-48,共4页
等离子体电极普克尔盒被广泛应用于大型激光驱动器中,用于抑制自激振荡、实现多程放大控制和反激光隔离,普克尔盒内的放电电极在长期使用过程中与腔内残余O_(2)发生反应出现退化现象,导致稳定性下降,寿命降低。为此,提出了封离型等离子... 等离子体电极普克尔盒被广泛应用于大型激光驱动器中,用于抑制自激振荡、实现多程放大控制和反激光隔离,普克尔盒内的放电电极在长期使用过程中与腔内残余O_(2)发生反应出现退化现象,导致稳定性下降,寿命降低。为此,提出了封离型等离子体电极普克尔盒,其放电腔内的Ne气浓度可达99.9%,漏率小于1.0×10^(−10)Pa∙m^(3)∙s^(−1),理论使用年限大于40年。实验表明,封离型等离子体电极普克尔盒在工作20万发次后,其放电电极依然光亮如新,时间抖动仍稳定在6.4 ns附近,稳定性有了大幅提升。 展开更多
关键词 电光开关 等离子体电极 普克尔盒 气体放电 封离型开关
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Small Cell关键技术和问题探讨 被引量:1
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作者 文万强 《电信技术》 2012年第S2期113-117,共5页
重点针对Small Cell部署过程当中引入的干扰、切换和传输进行分析,提出了解决方案和建议,其中有些方案尚处在探讨和完善阶段,还没有得到实际部署应用,仅供读者参考。
关键词 SMALL cell 干扰 切换 传输 维护
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An I/Q DAC with gain matching circuit for a wireless transmitter
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作者 汤华莲 庄奕琪 +1 位作者 景鑫 张丽 《Journal of Semiconductors》 EI CAS CSCD 2013年第6期126-131,共6页
This paper presents a two-channel 12-bit current-steering digital-to-analog converter(DAC) for I and Q signal paths in a wireless transmitter.The proposed DAC has a full-scale output current with an adjusting range ... This paper presents a two-channel 12-bit current-steering digital-to-analog converter(DAC) for I and Q signal paths in a wireless transmitter.The proposed DAC has a full-scale output current with an adjusting range of 2 to 10 mA.A gain matching circuit is proposed to reduce gain mismatch between the I and Q channels.The tuning range is±24%of full scale and the minimum resolution is 1/16 LSB.To further improve its dynamic performance, the switch driver and current cell are optimized to minimize glitch energy.The chip has been processed in a standard 0.13μm CMOS technology.Gain mismatch between a 1-channel DAC and a Q-channel DAC is measured to be approximately 0.13%.At 120-MSPS sample rate for 1 MHz sinusoidal signal,the spurious free dynamic range (SFDR) is 75 dB.The total power dissipation is 62 mW and has an active area of 1.08 mm^2. 展开更多
关键词 digital-to-analog converter GAIN MISMATCH switch current cell
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Energy Efficient Switch Policy for Small Cells 被引量:1
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作者 GAN Xiaoying WANG Luyang +4 位作者 FENG Xinxin LIU Jing YU Hui ZHANG Zhizhong LIU Haitao 《China Communications》 SCIE CSCD 2015年第1期78-88,共11页
Switch policy is essential for small cells to properly serve variable number of users in an energy efficient way.However,frequently switching small cell base stations(SBSs) may increase the network operating cost,espe... Switch policy is essential for small cells to properly serve variable number of users in an energy efficient way.However,frequently switching small cell base stations(SBSs) may increase the network operating cost,especially when there is an nonnegligible start-up energy cost.To this end,by observing the variety of user number,we focus on the design of a switch policy which minimize the cumulative energy consumption.A given user transmission rate is guaranteed and the capability of SBSs are limited as well.According to the knowledge on user number variety,we classify the energy consumption problem into two cases.In complete information case,to minimize the cumulative energy consumption,an offline solution is proposed according to critical segments.A heuristic algorithm for incomplete information case(HAIIC) is proposed by tracking the difference of cumulative energy consumption.The upper bound of the Energy Consumption Ratio(ECR) for HAIIC is derived as well.In addition,a practical Q-learning based probabilistic policy is proposed.Simulation results show that the proposed HAIIC algorithm is able to save energy efficiently. 展开更多
关键词 heterogeneous network small cell switch policy Q-LEARNING
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钠硫电池模块单体电压巡检系统设计 被引量:1
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作者 胡林权 王君艳 《现代电子技术》 2014年第1期101-103,共3页
以包含48个单体的钠硫电池模块为研究对象,针对现有两种常用的单体电压检测方法的不足,设计了一种改进的方案,运用光耦继电器依次对奇数编号和偶数编号的单体电压进行检测,从而实现对整个电池模块的巡检。仿真和测试结果表明该方案切实... 以包含48个单体的钠硫电池模块为研究对象,针对现有两种常用的单体电压检测方法的不足,设计了一种改进的方案,运用光耦继电器依次对奇数编号和偶数编号的单体电压进行检测,从而实现对整个电池模块的巡检。仿真和测试结果表明该方案切实、可行,具有良好的应用价值。 展开更多
关键词 钠硫电池 单体电压 巡检 开关切换
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LEO卫星移动通信系统空间网络技术分析
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作者 吴渭 骆连合 吴巍 《无线电通信技术》 2008年第4期11-13,共3页
在分析LEO卫星星座移动通信系统空间段网络功能和特点的基础上,进行了星座网络路由和交换技术体制的分析和论证,提出了以支持话音业务为主的LEO卫星移动通信系统星座网络路由和交换技术方案。星座网络采用定长信元格式交换体制,采用动... 在分析LEO卫星星座移动通信系统空间段网络功能和特点的基础上,进行了星座网络路由和交换技术体制的分析和论证,提出了以支持话音业务为主的LEO卫星移动通信系统星座网络路由和交换技术方案。星座网络采用定长信元格式交换体制,采用动态拓扑离散化的拓扑快照静态路由策略。这种静态路由离线计算方式和定长信元交换相结合,提高了网络交换的效率和转发速率。 展开更多
关键词 LEO卫星星座网络 信元交换 路由
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混合业务下基于能效准则的基站开/关选择策略
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作者 潘伟锵 胡少东 刘靖 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2015年第5期30-34,共5页
为提升无线系统的能效,针对用户随时间的潮汐变化特点,文中提出了一种通过基站开关切换提升系统能效的方法——基于能效准则的基站开/关选择策略,将用户业务分为恒定比特率业务和可变比特率业务,在满足恒定比特率业务的约束下最大化能... 为提升无线系统的能效,针对用户随时间的潮汐变化特点,文中提出了一种通过基站开关切换提升系统能效的方法——基于能效准则的基站开/关选择策略,将用户业务分为恒定比特率业务和可变比特率业务,在满足恒定比特率业务的约束下最大化能源效率.文中采用改进的自适应遗传算法来求解此约束优化问题,即基站开关状态用二进制编码,通过设计的选择、交叉、变异实现迭代寻优.仿真结果表明:文中提出的改进遗传算法收敛速度快,能有效对抗染色体群体的早熟问题;在满足恒定比特率用户需求的前提下,文中策略可有效地提升无线系统的能效,其性能接近穷举算法. 展开更多
关键词 基站开关 能效 遗传算法 约束优化
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NEWS
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《中国汽车(英文版)》 2005年第12期1-8,共8页
关键词 NEWS BORA FIRST LOCAL cell CARS RATE SERVICE SPACE switch
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